Gene Section Review Atlas Genet Cytogenet Oncol Haematol. 2010; 14(4) 423 Atlas of Genetics and Cytogenetics in Oncology and Haematology OPEN ACCESS JOURNAL AT INIST-CNRS TJP2 (tight junction protein 2 (zona occludens 2)) Lorenza Gonzalez-Mariscal, Erika Garay, Miguel Quiros, Rocio Tapia Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico DF, 07360, Mexico (LGM, EG, MQ, RT) Published in Atlas Database: May 2009 Online updated version: http://AtlasGeneticsOncology.org/Genes/TJP2ID44347ch9q21.html DOI: 10.4267/2042/44742 This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence. © 2010 Atlas of Genetics and Cytogenetics in Oncology and Haematology Identity Other names: MGC26306; X104; ZO2; ZO-2 HGNC (Hugo): TJP2 Location: 9q21.11 Local order: Telomeric to FXN gene (9q21.11). DNA/RNA Description TJP2 gene exists as a single copy in the human genome; it contains 25 exons and is predicted to span over approximately more than 90 Kb of the genomic DNA. Transcription Five isoforms of TJP2 have been identified: The A1 isoform (CDS: 3570 nt); lacks exons C and B The A2 isoform (CDS: 3129 nt); lacks exons C, B, 20 and 21. The A3 isoform (CDS: 2979 nt); lacks exons C, B, 20, 21, 22 and 23 and exhibits a longer exon 19 (979 vs 213 bp, with a stop codon at bp 313). The C1 isoform (CDS: 3501 nt); lacks exon A. The C2 isoform (CDS: 3057 nt); lacks exons A, 20 and 21. Schematic diagram of the TJP2 gene comprising 25 exons (in grey) and transcript variants. The sizes in base pairs of exons (above) and introns (below) are shown. *Indicates the position of the start codons. Exons C and B are expressed from promoter C. These exons are non-coding and translations starts from the ATG located in exon 2. Exon A is transcribed from promoter A. Isoforms C lack 23 aminoacids at the amino terminus in comparison with isoforms A. Exons 20 and 21 are alternatively spliced.